The present invention relates to video recording devices and more particularly to a video camera which stores successive frames in at least one circular buffer memory and which may continue to store frames for a period following the occurrence of a triggering event.
Numerous applications exist in which it is desirable to retain a video record for evidentiary or historical purposes. For example, in an automobile, or on a bicycle or motorcycle, it would be desirable to record a video image of the circumstances existing immediately prior to an accident and after an accident. Additionally, in security applications, it would be highly desirable to be able to record a video image of the circumstances existing immediately prior to an event triggering an alert condition and following the triggering of such a condition. Additionally, in numerous other applications it would be desirable to be able to create a video record of circumstances existing both before and after a triggering event.
A number of image recording devices are well known in the art. In time lapse photography a series of still pictures are taken over a period of time. Such pictures are typically taken with a periodically actuated still or a motion picture camera and employ photographic film. The cameras are loaded with a limited supply of film and the camera must be reloaded when the supply of film is exhausted. Accordingly, such devices are not well suited for applications in which it is desired to record images over a long period of time when only a very short period of time is of interest and the particular period of interest cannot be predicted.
In security applications, a video camera is often employed to record a video image on magnetic tape on a continuous basis. When the tape is exhausted it must be replaced.
Both photographic cameras employing photographic film and video cameras utilizing magnetic tape as the recording media employ mechanical transport mechanisms which are susceptible to failure when subjected to shock and vibration. Accordingly, such devices are ill suited for use in applications and environments in which shock and vibration are the norm.
For the above reasons, a video recording device would be desirable which could record video frames on a continuing basis and capture a video record of circumstances surrounding a triggering event occurring at an unpredictable time. It would further be desirable for such a device to be compact, lightweight, cost effective and avoid the aforementioned deficiencies of prior art video recording devices employing mechanical transports.